/Engine/Source/Runtime/GeometryFramework/Public/Components/BaseDynamicMeshSceneProxy.h
RecomputeRenderBufferTriangleIndexSets re-sorts the existing set of triangles in aFMeshRenderBufferSetinto primary and secondary index buffers. Note that UploadIndexBufferUpdate() must be called after this function!
void RecomputeRenderBufferTriangleIndexSets ( [FMeshRenderBufferSet](API\Runtime\GeometryFramework\Components\FMeshRenderBufferSet) * RenderBuffers, const [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) * Mesh )